Non-contact Workpiece Edge Contour Measurement via Multi-angle Reflection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for measuring the contour of workpiece edges, particularly for endless materials like steel strips, are inadequate as they require contact or reference measurements, leading to inefficiencies and unusable material due to impermissible deviations.

Innovation Solution

A non-contact method using multiple light sources arranged in a circular arc around the workpiece edge, with fixed positions and angular offsets, illuminating the edge at different angles to detect reflected light with optical sensors, allowing for precise contour determination without mechanical or optical reference measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If contact-free measurement methods are used, then measurement speed and productivity are improved, but measurement precision deteriorates due to inability to determine exact contour without reference measurements

Engineering Contradiction:
Improvemeasurement speedVSAvoidcontour determination accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The measurement process is segmented into multiple independent angular measurements taken at different incident angles. Each angle provides a separate measurement datum that, when combined with others, reconstructs the complete contour profile without requiring physical contact or reference objects.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The measurement approach transitions from single-angle 2D projection to multi-angle 3D contour reconstruction. By adding the angular dimension and taking measurements at multiple incident angles, the system achieves precise contour determination in three-dimensional space without contact.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If mechanical scanning methods are used, then measurement precision is improved through direct contact measurement, but productivity deteriorates due to time-consuming sequential scanning

Engineering Contradiction:
Improvecontour measurement accuracyVSAvoidmeasurement efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

Instead of sequential mechanical scanning, the system uses periodic illumination at multiple fixed angular positions. Multiple measurement points are captured simultaneously through optical means rather than sequentially through mechanical movement, dramatically improving measurement efficiency while maintaining precision.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The mechanical scanning system is replaced with an optical measurement system using multiple light sources at different angles. The physical contact and mechanical movement are substituted with non-contact optical detection, eliminating mechanical wear and increasing measurement speed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If reference measurements are used, then measurement reliability is improved by comparing against known standards, but device complexity increases due to additional reference components

Engineering Contradiction:
Improvemeasurement consistencyVSAvoidsystem configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The measurement system uses the workpiece itself as the measurement target without requiring separate reference standards. The multi-angle optical measurement inherently provides self-referencing capability by comparing measurements across different angles, eliminating the need for external reference objects and reducing system complexity.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If multiple light sources are used at different angles, then contour determination accuracy is improved, but device complexity increases due to additional light sources and positioning

Engineering Contradiction:
Improvecontour reconstruction accuracyVSAvoidillumination system configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Multiple light sources positioned at different angular positions are merged into a single integrated measurement system. The combined illumination from multiple angles provides comprehensive contour information that cannot be obtained from a single source, improving measurement accuracy while sharing common optical detection infrastructure.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables exact contour determination of workpiece edges without contact, reducing production interruptions and measurement errors, and ensuring operational reliability even in polluted environments.

Implementation Method 1

the workpiece edge is illuminated by at least one light source, so that a light beam incident on the workpiece edge in an extension in the first main direction X at an angle of incidence α with respect to the first main direction X is reflected into an associated reflected light beam

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

the reflected light beams are detected by at least one optical sensor with a detection direction Y, wherein the at least one optical sensor has an imaging height H

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP3575741B1Method for contact-free measurement of a workpiece edge
Publication Date: 2024.08.28 MANROLAND GOSS WEB SYST GMBH
  • EP3575741B1 patent drawingFigure 1a~1b
  • EP3575741B1 patent drawingFigure 2
  • EP3575741B1 patent drawingFigure 3

AI summary

The invention is therefore based on the objective of providing a solution with which any desired contour of a workpiece edge can be determined contactlessly based on the reflected light, without requiring reference measurements. This objective is achieved by a method in which the reflected light rays are detected by at least one optical sensor having an imaging height H, and the contour of the workpiece edge is calculated based on the radiation intensity of the reflected light rays detected by the optical sensor as a function of the contour-dependent exit angle β with respect to the angle of incidence α. The method according to the invention can, for example, be used for measuring cutting edges for razor blades during production.